Director-screenwriter

PARK CITY -- Lightly connecting a knock on the head to a long spell of bad behavior (or soul-searching adventures, depending on your point of view), Stacie Passon's Concussion stars Robin Weigert as a married woman who finds relief from a sexless marriage by becoming a prostitute. Its treatment of lesbian relationships, vulnerable to the same perils we've watched straight couples suffer onscreen for decades, will be appreciated by many viewers, though many will be put off by an unsympathetic protagonist.

Weigert's Abby shows us her ugliest side in the opening sequence, snapping "shut up, you shit!" at her own son after he accidentally beans her with a baseball. As she recovers from the wound, Abby seems to be newly sensitive to the superficiality of life as a stay-at-home mom in an unnamed well-to-do community near New York City. (Wife Kate, played by Julie Fain Lawrence, is a successful divorce lawyer.) She decides to buy a loft in the city and flip it, with renovations offering plenty of excuses to be away from home.

Particularly bothered by the lack of physical affection she gets from businesslike Kate, Abby goes to a prostitute, then another. In an eyebrow-raising coincidence -- not the last, or the least credible, in this film -- Abby's contractor Justin (Johnathan Tchaikovsky) has just started dating a college student who runs call girls on the side; he offers Abby a chance to make money exploring her sexual wanderlust.

What follows is sometimes poignant (the overweight virgin prompted by a women's studies course to rent a date), sometimes psychologically intriguing (an older woman who nearly talks herself out of doing what she has paid for) and sometimes exciting. But a tough-to-buy encounter with a sexy housewife (Maggie Siff) who's part of Abby's social circle introduces dangers that aren't satisfactorily explored, and the inevitable confrontation with Kate is similarly unsatisfying.

Although Weigert is convincing as Abby, Passon's attitude toward the character is hazy. Are these illicit experiences meant to redeem the problematic character in some way? Are they anything more than a reminder of her wild days as a punk-loving aesthete? By the film's end, the character -- whose married life boils down to making choices between khaki, parchment and beige -- seems unchanged, and Concussion can't decide if that's a good thing or bad.